The Immigration Department and Interpol have issued contradicting statements regarding the stolen passports used by two Iranians to board flight MH370.

Contrary to Interpol's version, Immigration director-general Aloyah Mamat ( left ) said the pair had entered Malaysia with the stolen Italian and Austrian passports respectively.

She said Pouria Nourmohammadi, 19, had arrived at the Kuala Lumpur International Airport (KLIA) on Feb 28 at 8.28pm and produced an Austrian passport.

The second Iranian, Delavar Seyed-mohammaderza, 29, had arrived at KLIA on March 7 at 10.43pm with an Italian passport.

Aloyah said both men were allowed in based on standard operating procedure by immigration officers who did not suspect something was amiss.

However, Interpol’s version as reported by Reuters was that the duo had travelled from Doha to Kuala Lumpur using their Iranian passports.

Based on Interpol secretary-general Ronald Noble’s statements, the duo had only used the stolen passports in Malaysia when boarding the flight bound for China on March 8.

In its official statement, Interpol had also stated that the National Central Bureau in Tehran had confirmed the identity of two Iranian nationals "who used authentic passports to travel to Kuala Lumpur".

The Immigration Department had been drawing flak for not detecting the stolen passports, with Home Minister Ahmad Zahid Hamidi vowing a thorough probe .

In defending the department, acting Transport Minister Hishammuddin Hussein ( right ) later said that the Interpol database contained a list of 40 million stolen passports, thus making the task of cross-checking next to impossible.

News of the stolen passports had also fueled concerns over a possible terrorist attack, but the Malaysian police had cleared the Iranian duo of any terror links.        

Contacted twice by Malaysiakini this morning, Aloyah refused to entertain questions regarding the contradiction.

"Refer to what I said at the press conference yesterday," she said and cut the line.

The Boeing 777 jet, with 239 people on board, has been missing since Saturday morning.

Additional reporting by Farah Noor Samat