Peter Bellew has denied Pakatan Harapan chairperson Dr Mahathir Mohamad's claim that his departure as chief executive officer of Malaysia Airlines (MAS) was due to Prime Minister Najib Abdul Razak's interference.

"(Mahathir) as a leader, who back in 1981 became the prime minister, did some great things for this country.

"But Mahathir is completely wrong in his accusations about me in the last 72 hours. He's a 100 percent wrong," Bellew told a press conference in Petaling Jaya today.

He said no one connected to Mahathir had been in touch with him to verify the facts of the matter.

"I have had no interference from anyone on anything to do with running the business over the last two years," Bellew said.

Mahathir (photo), who is also Bersatu chairperson, had in a blog posting on Friday claim that Bellew quit due to the prime minister's interference in the MAS management.

Bellew stressed that his decision to quit was of his own accord.

"It's very simple, I just want to 'balik kampung' to Ireland, back to the people I love.

"There's no mystery, there's no intrigue, there's no controversy around that, as far as I'm concerned," he said.

He said he was compelled to hold the press conference despite having issued a statement a few days ago, due to the accusations made by Mahathir. 

"I felt I need to clear the air. Also, many media requested we meet one last time and this is the one last time. I won't be doing any more press or media (meets) after this," he said.

Asked if he was instructed by the authorities to hold the press conference, Bellew replied: "No."

"Most of you who know me by now would know that it's quite difficult to tell me to do anything. The only person that can tell me to do something is my wife," he added.

Bellew, meanwhile, also denied that he was leaving MAS due to Boeing aircraft orders which Najib announced in his meeting with US President Donald Trump in September.

"That is completely untrue, 100 percent incorrect. Not a shred of truth in that statement. 

"There was no political interference in MAS' decision to buy Boeing or Airbus," he said.

The airline, he explained, simply needed more widebody planes and fewer narrowbodies. 

"The chairperson and I brought the memorandum of understanding to the prime minister in Washington and he witnessed the signing. It all came from MAS," he insisted. 

Mahathir had been extremely critical of the Boeing purchases, saying it would add to problems that would affect MAS' bottom-line.

Bellew, however, claimed that Mahathir had highlighted in his book his own "failures" on MAS which led to its downfall. 

"In fact, across 200 pages in his own book he completely contradicts himself," said Bellew, citing several excerpts from Mahathir's memoir "A Doctor in the House".

Bellew also refused to respond to the National Union of Flight Attendants Malaysia (Nufam) which had expressed its lack of confidence in Khazanah Nasional Berhad’s plan to resuscitate the airline.

"I have no comment on Nufam, I think they have their own interests," he said.

Khazanah had put in place a 12-point recovery plan for the airline when it became the airline’s sole shareholder in 2015.

Nufam president Ismail Nasaruddin on Friday said Bellew's departure was more proof that the fund’s efforts to save MAS have been futile.