THE police force investigating the Lockerbie bombing has increased the number of officers involved in the inquiry.

Dumfries and Galloway Constabulary said the move was due to regime change in Libya.

A total of 270 people were killed when Pan Am Flight 103 exploded over Lockerbie on December 21, 1988.

Abdelbasset Ali Mohmed al Megrahi was convicted of the bombing and sentenced to life imprisonment in 2001. He was released on compassionate grounds in August 2009 after being diagnosed with terminal cancer and was returned to Libya. At the time, doctors estimated he had three months to live. He is still alive.

Dumfries and Galloway officers who are investigating the bombing met Libyan defector Moussa Koussa last April. Former foreign minister Mr Koussa is believed to have been an intelligence officer at the time of the Lockerbie bombing.

Libya's National Transitional Council has said it would co-operate with any investigations.

Dumfries and Galloway Constabulary would not comment on how many officers are now involved, saying it was an "operational matter".

On the 23rd anniversary of the bombing last month, Scotland's most senior law officer vowed to bring the perpetrators to justice. Lord Advocate Frank Mulholland said the idea Megrahi acted alone was "risible", and added that he would be "failing in his duty" if he did not find the people responsible.

The Crown Office said: "The transitional Government of Libya has agreed to allow officers from Dumfries and Galloway police to travel to Libya for inquiries into the involvement of others with Mr Megrahi."