Nicola Sturgeon returns to parliament after arrest

Nicola Sturgeon has returned to the Scottish Parliament for the first time since being arrested as part of an investigation into SNP finances.

The former first minister was released without charge after being questioned by Police Scotland for more than seven hours last week.

She told reporters at Holyrood that she is "absolutely certain" she has done nothing wrong.

She also indicated she would not resign from the SNP.

Ms Sturgeon, who stood down as both party leader and first minister in March, said the party had been her life and she would always act in its best interests.

She said: "I'm back in parliament today getting on with my job representing my constituents."

The former first minister told reporters she was "heavily constrained" on what she could say about the police investigation, adding: "I respect understand the process that is underway, but I am absolutely certain that I have done nothing wrong."

Questioned on whether she should stand down from the SNP, she said she would always consider what is best for the party.

Ms Sturgeon said it had not been an "easy" period in her life. "The thing that sustains me right now is the certainty that I have done nothing wrong," she told reporters.

The former first minister also insisted that the investigation had not "shaken" her belief that the case for Scottish independence was getting "stronger every day".

Her successor, Humza Yousaf, has been under pressure from opposition parties and some within the SNP to suspend Ms Sturgeon while the police investigation is ongoing.

After her arrest and subsequent release he described Ms Sturgeon as being "the most impressive politician I think we have seen in Europe" and described her as "an asset to our movement, and to our party".

SNP MSPs also agreed to send flowers to the former first minister "as an expression of our support" after a group meeting at Holyrood last week.

Ms Sturgeon spoke to reporters outside her home in Glasgow on Sunday - the first time she had been seen in public since her arrest on 11 June.

Shortly after being released from custody pending further investigations she released a statement on social media which stated she would "never do anything to harm either the SNP or the country".

Her latest statement came after a Panelbase poll for the Sunday Times suggested that Labour could be on track to win more seats than the SNP in a Westminster election for the first time since 2010, with Mr Yousaf's party projected to go from 45 seats to 21.

The poll, conducted in the days after Ms Sturgeon's arrest, also suggested that her personal approval rating has fallen by 38 points since February, from plus 20 to minus 18.

Police Scotland's investigation, named Operation Branchform, is looking into what happened to more than £600,000 of donations given to the SNP by independence activists.

Officers searched Ms Sturgeon's home and the SNP's headquarters in Edinburgh on 5 April.

Former SNP chief executive Peter Murrell, who is also Ms Sturgeon's husband, was arrested and released without charge pending further investigation.

A luxury motorhome which costs about £110,000 was also seized by police from outside the home of Mr Murrell's mother in Dunfermline.

Almost two weeks later, SNP treasurer Colin Beattie was arrested and released without charge while further inquiries were carried out.

Mr Beattie resigned as party treasurer shortly afterwards.

Ms Sturgeon, Mr Murrell and Mr Beattie were the three signatories on the SNP's accounts and the arrest of the former first minister had been widely expected.

Ms Sturgeon has previously denied that her decision to resign as first minister and SNP leader earlier this year was influenced by the police investigation.