The English Football Association (FA) has closed an investigation into allegations that employees of Liverpool hacked into Manchester City's scouting system.

The incident stretches back to 2013 when Liverpool are alleged to have hacked a player database used by City scouts.

Reports last year stated that the case between the two clubs had been settled for a £1 million ($1.3 million) compensation payment by Liverpool, but that they never accepted any liability or wrongdoing.

"The FA has carefully considered the evidence it received in this matter, including information provided by both clubs involved, and has decided not to progress the investigation," the FA said in a statement on Friday. "This is due to a number of factors including the age of the alleged concerns and the settlement agreed by the two clubs involved." The case has heightened the tension between the clubs as they battle for supremacy in the Premier League.

Liverpool are romping towards a first league title in 30 years as they hold a 22-point lead over City, who beat them to the title by just one point last season.

City's team bus was also attacked by Liverpool fans ahead of a Champions League quarter-final won by the Reds in 2018.

And Raheem Sterling was suspended for one match by England manager Gareth Southgate for an altercation with Liverpool defender Joe Gomez when they met up for international duty a day after a bad-tempered 3-1 defeat for City at Anfield.