Singer Paolo Nutini was seen behind the wheel of a Mini after ordering vodka in a bar, a court has heard.

Witness Colin May said he saw Nutini and a friend ordering rounds in DeBeers bar in Paisley, Renfrewshire.

He reported the singer to police after spotting him driving a car shortly after leaving the pub on February 21 this year, Paisley Sheriff Court heard.

Nutini, 30, is on trial accused of driving on various streets in Paisley while more than twice the legal limit on February 21.

It is alleged he drove with 48 microgrammes of alcohol in 100 millilitres of breath, exceeding the limit of 22 microgrammes in 100 millilitres of breath.

The Blue Shoes singer denies the charge.

His defence agent Massimo Franchi said his defence is "post-incident drinking".

Mr May told the court that he went into DeBeers pub at about 10.10pm on February 21 and took a seat at the bar.

He became aware of Mr Nutini sitting at a table with another man and a woman.

During the hour and a half he spent in the bar, he noticed Mr Nutini buy one round at the bar and the other man buy two rounds, he said.

Fiscal Depute Frank Clarke, prosecuting, asked: "Were you able to hear what was ordered?"

He replied: "From memory, I believe it was vodka, more than one, but I could not be certain of that."

Asked how many people were at the table, he replied: "I could not see the table."

Mr May said Nutini left the bar about ten minutes before him and he next saw him about 15 minutes later in the driver seat of a black Mini at traffic lights on Maxwellton Street and Canal Street, with a woman in the car.

The prosecutor asked: "On seeing this Mini driver and recognising Mr Nutini, what were your thoughts?"

He answered: "I had seen him drinking at the bar having more than what would be the legal limit of one to two drinks."

He added: "At first I was a bit thrown and continued my journey home, then I called the police to tell them what I had seen."

During cross-examination, Mr May agreed Mr Nutini was sitting behind him.

Mr Franchi asked: "He goes back to his table and you don't know what happens, those drinks could have been spilled, you don't know", to which Mr May agreed.

The defence agent also asked whether Mr Nutini could have been ordering a soft drink, saying: "You cannot tell the court if he ordered vodka or soda and lime."

Mr May replied: "I believe I heard vodka being ordered but not anything else."

The court also heard from police officer Laura Murray, who was called to Canal Street towards midnight on February 21 to a report of a car being driven by someone who had allegedly been drinking.

The car was no longer there when they arrived but they went to an address where they found a grey Mini and Mr Nutini, who they had been told was the driver of the vehicle.

Pc Murray said she told Mr Nutini he would need to do a breath test.

Mr Clarke said: "Did you ask when his last drink was?"

She replied: "He said it was ten minutes before police arrived."

The police officer told the court Mr Nutini tested positive for alcohol and was then arrested and taken to Govan police office for a further test.

Pc Murray was sitting next to the singer in the back seat on the journey to the police station.

Asked whether he spoke during the journey, she said: "The accused was speaking freely in the back of the car stating that he had been at DeBeers that night watching football with friends and consuming alcohol. He said he had been drinking vodka with friends."

She said he did not specify how much vodka.

Mr Clarke asked: "Did you remind him he was under caution?"

She replied: "Yes, he was very apologetic, saying he realised he had done wrong and was stupid for his actions.

"He said he had driven his car home that night as he was fearful of leaving it in the town centre area in Paisley as it might get damaged."

Asked whether he mentioned drinking when he got home, she said: "He said he had had a mouthful of wine at home and this later changed to saying he had a mouthful of whisky."

When the breath test was carried out, it gave a reading of 48 microgrammes and he was charged as this exceeded the limit.

The court heard that when he was charged, Mr Nutini said: "I feel like the drink I may have had after the said charge may have affected this."

Asked what she took this to mean, Pc Murray said: "That he might have felt the alcohol he consumed in the house might have affected this reading."