A Surbiton man punched and kicked a mother of three at a Barcelona cashpoint before returning with a knife to stab her to death, a Spanish court has been told.

Sean Heiss, who was living in St Mark’s Hill, has been in custody in Spain since he was accused of murdering a woman described by the court only by her first name Clementina on September 29, 2012.

The trial is being followed by UK police who suspect Mr Heiss murdered his own mother Margot Sheehy in her Springfield Road flat before going on the run to Spain.

In a document filed at the beginning of a trial in Barcelona on Friday, the Spanish prosecutor described an attack in which Mr Heiss, 30, is alleged to have punched, kicked and stabbed the woman in the head and face as she entered the cash machine area at about 7am.

The prosecutor wrote: "Clementina went to the La Caixa cashpoint on the corner of Paris and Aribau streets in Barcelona, where she found the accused.

"He opened the door and, approaching Clementina, began to hit her, causing her to fall to the floor.

"While she was on the floor, the accused continued hitting her in the face and head with strong and repeated strikes of his feet and/or fists.

"After this the accused went back into the cashpoint and took a knife from his personal effects, with which he returned to where he had left Clementina.

"He repeatedly stabbed her in the throat and face, continuing to land blows and kicks, intending to kill her or, at least, knowing that her death would result from the attack.

"Clementina was taken to the Hospital Clinico de Barcelona where she eventually died at 1.50pm the same day as a consequence of hypovolemic shock produced by the penetrative knife wounds, and by head wounds suffered as a result of the punches.

"Clementina could not put up an effective defence against the attack, because the accused continued hitting her as she lay stunned by the pain and stretched out on the floor."

According to the document, known as 'calificaciones', the prosecutor is seeking a 25-year sentence for murder if Mr Heiss is found guilty.

Mr Heiss could also have to compensate the woman's three children, her parents, and her partner, amounting to several hundred thousand Euros.

Her children, two boys and a girl, are between 9 and 13 years old.

Mr Heiss is being tried by a jury of 11 people, the Tribunal Superior de la Justicia in Catalonia said.

According to the public prosecutor's filings, the jury will hear evidence from Mr Heiss, as well as witnesses.

The victim's mother and partner will give evidence, as will the police officer who arrested Mr Heiss, and another who took photos of the aftermath and Mr Heiss' hands.

Information on Mr Heiss' mental and physical state will also be presented.

Police in the UK had issued a European arrest warrant for Mr Heiss after his mother, Margot Sheehy, was found dead in her ground floor Springfield Road flat in June 2012, having been being asphyxiated.

They thought they had caught him and had begun the extradition process when he was arrested by Spanish police in San Sebastian 10 days later, after allegations he threatened a woman with a knife, but he was allowed to walk away in an apparent blunder.

According to Spanish newspapers El Periódico and El País, Mr Heiss was homeless and sleeping rough in Barcelona when he was finally arrested in October.