NICOLA Sturgeon banned disgraced former finance secretary Derek Mackay from going out drinking during conferences due to concerns over his behaviour, it has been claimed.

Mr Mackay, who yesterday resigned from his role and was suspended from the SNP, even joked at the 2017 party conference that attendees would not be seeing him at the pub after the event as “Nicola won’t let me”.

A former senior staff member told our sister title The Herald the First Minister advised the MSP not to go out partying after his behaviour came up at senior staff meetings.

It comes after revelations Mr Mackay bombarded a schoolboy he befriended on Facebook and Instagram with hundreds of online messages over a six-month period – including one calling him “really cute”.

The messages, which were published in the Scottish Sun and sent shockwaves through Holyrood, continued even after the boy revealed he was still in school, and then later said he was 16.

READ MORE: Police probe into messages sent by Derek Mackay to 16-year-old schoolboy

Scottish Conservative interim leader Jackson Carlaw said Mr Mackay’s “grooming-style behaviour is completely disgraceful” and said it was hard to see how he can continue as an MSP.

Scottish Labour leader Richard Leonard said Mr Mackay’s actions were “predatory and must be thoroughly investigated”, adding: “He has abused his position of power with a vulnerable adolescent.”

Police Scotland said it had not received any complaint of criminality, but added: “We are currently assessing available information from media reporting and would encourage anyone with information to please come forward.”

Mr Mackay resigned as finance secretary on Wednesday night, on the eve of the £40 billion draft Scottish Budget.

Yesterday, Ms Sturgeon told MSPs he had also been suspended from both the SNP and its parliamentary group “pending further investigation”.

Mr Mackay, a father-of-two who came out as gay in 2013, was once tipped as a future First Minister. But Ms Sturgeon said his behaviour fell “seriously below” the standards required of a minister.

She also said there are “clearly” issues for Mr Mackay to reflect on in terms of whether he continues as an MSP. Ms Sturgeon was met with a wall of television cameras and microphones as she left the Holyrood chamber following First Minister’s Questions.

READ MORE: Derek Mackay branded 'predatory' and urged to resign as MSP

Asked whether Mr Mackay should continue as an MSP, she said: “I am making my views very clear. He has issues to reflect on.”

Following Mr Mackay’s rapid downfall, public finance minister Kate Forbes, 29, a first-term parliamentarian, was forced to step up and set out the draft Scottish Budget with less than a day’s notice.

Mr Mackay accepted he had “behaved foolishly” as he apologised unreservedly to the boy and his family.

In one message, he asked the teenager: “And our chats are between us?”

When the boy agreed, Mr Mackay told him: “Cool, then to be honest I think you are really cute.”