A Holyrood committee has rejected a call to close a petition demanding an independent inquiry into the Lockerbie bomber's conviction.

Instead MSPs on the Scottish Parliament's Justice Committee are hoping to find out if moves have been made that could lead to a further appeal on behalf of Abdelbaset al-Megrahi.

The committee is to contact the Scottish Criminal Cases Review Commission (SCCRC) - an independent body which investigates where there are concerns about a possible miscarriage of justice.

Sir Stephen House, the Chief Constable of Police Scotland, will also be written to, as MSPs are worried allegations about the original Lockerbie investigation are being sidelined.

The Justice for Megrahi campaign, which put forward the petition calling for an independent investigation into the Libyan's conviction, has also made allegations of "criminality during the investigation of the Lockerbie disaster".

Detective Superintendent Stuart Johnstone has written to the group's secretary, Robert Forrester, saying a "conflict" with the live investigation into the case remains "unresolved"

Tory MSP Margaret Mitchell said these matters took the committee "off at a tangent" from the petition's original call for an inquiry in Megrahi's conviction.

She said: "We could close the petition today because the Scottish Government has said quite categorically it has no plans for a review.

"I would be inclined to close it today because we're going off at a tangent."

The committee rejected that, with independent MSP John Finnie saying such a move would be "inappropriate" when there was an "ongoing live criminal inquiry".

MSPs will write to the SCCRC to find out if it has been approached to review the case.

Committee convener Christine Grahame said they would be seeking to discover if "any application or inquiry has been made, an application by any member of the Megrahi family or anyone with an interest" to the SCCRC - which reviews cases before deciding whether or not to refer them on to the courts.

Ms Grahame added she was "very cross" with the lack of information regarding any investigation into Justice for Megrahi's allegations of criminality in the original Lockerbie investigation.

Mr Finnie said these were "allegations of serious criminality in what was a mass murder case", as he accused the authorities of "procrastination and obstruction" .

Ms Grahame said: "You call it procrastination and obstruction, I call it long grass. If there's any strategy here with regard to the Megrahi issue it seems to be to kick things into the long grass, wear people out, hope those who are pursuing this fall off their perches and it all goes away."

She said MSPs had been told by the police in September it would be "a matter of weeks" before they "would be able to confirm the investigation had fully commenced", but were still no further forward.

Ms Grahame hit out: "This is nonsense. I just think this is contemptuous of the committee. We are being told weeks, then it becomes months. Not good enough.

"I am concerned that if the Justice Committee is being treated in this rather off-hand fashion, goodness knows what is happening elsewhere."

She said: "I think we should be writing directly to the Chief Constable and asking him how many people are currently working on the inquiry and what the position is with regard to another inquiry. I think it's time we went to the top of the tree."

Megrahi is the only person to have been convicted of the bombing of Pan Am flight 103 over Scotland, in which 270 people were killed.

He was given a life sentence but was controversially released from jail by the Scottish Government on compassionate grounds in August 2009 after being diagnosed with prostate cancer. He died protesting his innocence in Tripoli in May 2012.

In December, the Libyan attorney general announced he had appointed two prosecutors to work on the case. For the first time they met Scottish and US investigators who are trying to establish whether there are other individuals in Libya who could be brought to trial for involvement in the attack.