Controversial Australian government contractor Paladin is suspected of abusing taxpayer funds to bribe then-Papua New Guinea police minister Jelta Wong to enable the firm to run the federal government’s offshore detention regime.

The suspicions are detailed in police documents sighted by this masthead and come after federal agents seized the phone of a suspected Paladin middleman after he flew into Australia.

That device uncovered what one official source said was highly valuable material for the investigation of suspected corruption involving Australian businesses and high-ranking PNG officials.

The federal police are also investigating Paladin for dishonestly obtaining millions of dollars from Australian taxpayers via the Home Affairs offshore detention budget to fund suspected bribery.

Police documents presented to a judicial officer to authorise police raids and the seizure of potential evidence detail how Paladin is suspected of having “dishonestly obtained a gain from the Australian Department of Home Affairs … by lodging false claims for the reimbursement of money used to bribe foreign public officials”.

The suspicions raise fresh questions not only about the suspected corruption of the offshore detention programme by government contractors, but also about the role of Australia’s National Anti-Corruption Commission (NACC) in investigating the allegations. Nobody has been charged and this masthead is not suggesting a crime has been committed, a finding that can only be made by a court.

The NACC last week released a short report that cleared Paladin over conflict-of-interest allegations involving dealings between the firm’s founder, Craig Thrupp, and his mother, who was an official at Home Affairs when the firm first won contracts to manage offshore detention that would balloon to over $500 million(US$333 million).

The report, completed by NACC’s predecessor, the Australian Commission for Law Enforcement Integrity, found that Thrupp’s relationship with his mother had been appropriately disclosed during Paladin’s pitch for government work and payments he made to her did not breach public service rules.

The report said it sought to “clear the air” around Paladin but made no mention of the bribery suspicions still under AFP investigation involving Thrupp, Paladin and the suspected bribery of PNG politicians.

The NACC, which does not comment on specific investigations, has the power to probe Paladin as a government contractor, but may also choose to leave such inquiries to the AFP, as has occurred in the PNG suspected bribery case, according to police insiders not authorised to speak publicly.

The Paladin police probe is sensitive for the Albanese government given it involves Wong, who is currently health minister of PNG.

Wong denied receiving any payment from Paladin, saying in a statement that he was “surprised and deeply concerned by the allegations.”

“From my knowledge and recollection, Paladin was awarded the contract for the detention centre by the Australian government,” he said.

Thrupp did not respond to a request for comment but has previously denied any wrongdoing in the company’s dealings with officials.

A former company executive said they knew of “absolutely no payments whatsoever” made to PNG ministers.

The examination of Paladin’s conduct comes after the closure of the Australian government-funded asylum seeker processing centre on Manus Island.

PNG is a key regional ally of Australia but is caught between Canberra and Beijing in the battle for influence in the Pacific.

According to senior officials in Canberra who have spoken to this masthead on condition of anonymity, the Australian government is seeking to combat corruption in the region while also preserving diplomatic ties, often leading to efforts to suppress details of foreign official corruption that might emerge in court cases.

In a separate corruption matter where charges have been laid, the Department of Foreign Affairs and Trade last week moved to suppress details of allegations that a Gold Coast mining firm bribed Nauru government officials.

The AFP’s investigation into Paladin was first revealed in February by this masthead, but the police documents mark the first time that police-turned-health minister Wong’s name has been connected to it.

Wong was among those named as a suspected bribery recipient in an application by the AFP to conduct search and seizure activities in several Australian states, including Queensland.

The police activity has also targeted a wealthy Australian-PNG businessman, named in the police applications as Justin Chongsen Tan.

Two official sources have confirmed that Tan’s phone records have been seized by police, casting light on his relationship with multiple PNG officials. Tan was recently named in a Queensland court case involving a bikie gang shooting up his Brisbane mansion in connection to an Australian business dispute.

He was not accused of wrongdoing in that case. The AFP’s probe is unconnected to the bikie shooting.

The AFP case involves suspicions that Tan may have been used by Paladin to pay up to $3 million (US$1.99 million) to Wong to secure support for the firm’s offshore detention operations.

The documents reveal suspicions that Thrupp and Paladin paid the funds “between 21 September 2017 and 30 November 2019” with the “intention of influencing a foreign public official in the exercise of the official’s duties … in order to retain business”.

Wong said that while he did know Tan, he “vehemently” denied receiving any “payment or bribe from Paladin via Justin Tan”.

“I take great exception to the allegation and will be seeking appropriate legal advice should any publication be made which alleges that I received a bribe from Paladin. I trust this clarifies my position,” he said.

In February this year, this masthead revealed how ex-spy chief Dennis Richardson had referred Paladin to the federal police for investigation over concerns about its management of large contracts it won from Home Affairs to run offshore detention on Manus Island.

The reports also disclosed internal corporate files showing how Thrupp personally made more than $150 million (US$99 million) after Paladin won Home Affairs contracts ultimately worth more than $500 million (US$333 million) over four years to run offshore processing on PNG’s Manus Island up to 2019.

Via another of his companies, Thrupp has since purchased a $33 million (US$21 million) luxury yacht and multiple properties, including an exclusive clifftop property on the coast of Bali.

In an interview, Richardson raised serious concerns about Home Affairs’ dealings with Paladin.

Of Paladin’s profit margins, Richardson said: “Even taking into account the risks, it was still quite exceptional.