A Holyrood committee has called on Scotland's parliamentary watchdog to investigate harassment claims against Mark McDonald MSP.

The standards committee announced the move on Thursday after SNP MSP James Dornan wrote to the body alleging a member of his staff "was a targeted victim of harassment and sexual innuendo" by the Aberdeen Donside MSP.

McDonald resigned from the SNP last week after an internal party investigation found that he had exploited "his position of power" as an MSP over two women, sent "unwanted text and social media messages" and his behaviour caused distress to those involved.

In a letter to the committee, Dornan said on one occasion his employee asked him to escort her out the building after an event as "she was sure McDonald was waiting for her".

He alleges when they left the Scottish Parliament the Aberdeen Donside MSP was "standing close to the exit" and it left "no doubt he was indeed waiting for her".

In a statement on Monday to STV News, McDonald said: "I refute any suggestion I was waiting in the parliament for the individual in question after an event, and refuted this during the investigation process."

Standards committee convener Clare Haughey said: "Under the Commissioner's Act, the committee may refer certain complaints to the commissioner for ethical standards in public life for investigation.

"Broadly speaking, the role of the Commissioner is to independently establish the facts of a complaint.

"The committee will then consider whether it agrees with the Commissioner's findings and any question of sanctions.

"We believe this is the most appropriate way of handling this complaint.

"The Commissioner is resourced to carry out this type of investigatory work, although we appreciate the sensitivities associated with this unique area.

"We do not think it would be appropriate for the committee to undertake its own investigation and there is no procedure or precedent for the Committee to do so.

"We understand that due process must be followed and this will take time regardless of who carries out the investigation.

"It is in no one's interest that this process becomes drawn out."