The whereabouts of John Attard Montalto during a crucial vote on the new Frontex guidelines in the European Parliament over a week ago remains a mystery after the Labour MEP failed to answer questions from The Sunday Times.

Speculation in Brussels has suggested that the flamboyant Labour MEP was on holiday on the Indian Ocean island of Madagascar while the EP was voting on an issue which had a direct impact on his home country.

When asked to explain his absence during the vote, Dr Attard Montalto's office ignored the questions sent by e-mail while the MEP failed to respond to calls or text messages.

The Sunday Times encountered another similar brick wall when it approached Labour's head of delegation in Brussels, Louis Grech, for a response.

He ignored questions sent by e-mail and when contacted by phone Mr Grech said he was unable to talk as he was "busy in a meeting". He never returned the call.

Through its vote on March 25, the EP approved a set of new guidelines to serve as a code of engagement on future immigration patrols in the Mediterranean similar to the ones that have taken place off Malta's coast for the past four years.

The new guidelines work against Malta as they place the onus on the country hosting the mission for the disembarkation of all immigrants and asylum seekers saved at sea during a Frontex mission.

Despite breaking ranks with the Socialist Group which was in favour of the new rules, the votes of Mr Grech and the other Labour MEP, Edward Scicluna, were not enough to obtain the qualified majority needed to prevent them coming into force. The EPP and the Liberals, the other big political forces in the EP, voted to reject the rules.

Malta said it would not be taking part in any future Frontex missions under the new guidelines. Home Affairs Commissioner Cecilia Malmstrom said she will try to engage Malta again and will be conducting further discussions in an attempt to reach agreement on the issue.