The Australian senator ordered to be deported by Malaysia as a ''security risk'' previously acted as an emissary for Malaysia's opposition leader, Anwar Ibrahim, carrying a warning letter to the federal government.
The South Australian senator Nick Xenophon was detained at Kuala Lumpur airport on Saturday after being told there was a technical hitch with his passport and was then escorted to a holding cells area, although he was not put in a cell.
Speaking from the airport, Senator Xenophon described his detention as bizarre. "They have told me I am a security risk," he said.
In a separate interview with Sky News, he said: ''I was eventually told apologetically by immigration officials that I am on a watch-list, that there are orders from above in terms of security concerns, and I have to be deported.''
Only hours before Senator Xenophon's arrest, Mr Anwar criticised the Foreign Affairs Minister, Bob Carr, in an interview with Fairfax Media, revealing he had asked in the letter for Australia to speak out about Malaysia's rigged political system.
Mr Anwar, who heads a three-party opposition alliance, said Senator Carr was "ill-advised or clearly lacks an understanding" of what is happening in Malaysia when he refused to act on the letter, sent late last year.
Senator Carr has raised Australia's concerns with the Malaysian government about Senator Xenophon's detention.
"Senator Xenophon's detention is a surprising and disappointing act from a country with which Australia routinely maintains strong diplomatic relations," he said.
Senator Carr said Australia's high commissioner in Kuala Lumpur, who had spoken to Senator Xenophon, was "seeking an explanation from Malaysian authorities regarding the reasons for this detention".
Senator Xenophon was in Malaysia leading a bipartisan group of Australian politicians for talks with the country's opposition parties about electoral systems. He has been highly critical of the preparations for the election to be held this year.
In particular, he has raised concerns about the integrity of Malaysia's electoral rolls.
Senator Xenophon was in a delegation with other Australian MPs including the Liberal Mal Washer, Labor's Steve Georganas and Nationals senator John Williams. The others were due to fly out on Monday but have cancelled their visit in protest.
I just wanted to arrive here quietly and work.
''It seems a member of the Australian Parliament is now not allowed into Malaysia because I am a supposed security risk,'' Senator Xenophon said.
''I just wanted to arrive here quietly and do our work. I didn't ask to be deported, believe me.''
In a statement issued after Senator Xenophon's arrest, Mr Anwar condemned the Malaysian government's actions.
''Prime Minister Najib Razak has no right to treat visitors as enemies of the state merely because they are critical of his UMNO-led administration,'' he said.
''This act of detention and proposed deportation for partisan political reasons is therefore a gross abuse of power.''
In the interview that preceded Senator Xenophon's arrest, Mr Anwar attacked the Gillard government for its failure to speak out about electoral fraud ahead of his country's fiercely fought election.
However, after a meeting and receiving the letter from Mr Anwar, Senator Carr told the ABC Malaysia's elections were a matter for the Malaysian people.
"It's very hard for Australia to do anything about how they're run," Senator Carr said.
The Malaysian election must be called within weeks, but the parties have been campaigning for months.