Premier League clubs spent a record £1.4billion on players this summer, including an unprecedented £210million on transfer deadline day, according to football finance experts Deloitte.

This late flurry of spending took the league's overall outlay on players since the first transfer window in January 2003 past £10billion.

The total summer spend in England's top flight was up 23 per cent on last year's record figure, which is already a record amount for a single season and a new milestone for a calendar year.

But with several major transfers falling through at the 11th hour yesterday, the league's net spend was £20million less than last summer's record of £685million.

Despite that slight dip in net spend, the clubs combined to shell out an estimated 31 per cent of their revenues for this season, a significant rise on the average summer window spending-to-revenue ratio of 22 per cent.

Commenting on the numbers, Deloitte's Dan Jones said: "Premier League clubs have broken their own record for transfer expenditure for the sixth summer in a row.

"With the continued growth in clubs' revenues, principally from broadcast rights, it is no surprise that Premier League clubs have continued to maintain their leading position in the world's player transfer market.

"Importantly, and when analysed in the context of generating record broadcast, commercial and matchday revenues, Premier League clubs are spending well within their means.

"For the last 15 years, annual transfer spending has remained within the range of between a fifth and a third, and averaged at around a quarter, of total revenues.

"With Premier League clubs' revenue showing no sign of decreasing in the foreseeable future, we would expect to see spending continue to rise."

Despite Paris Saint-German splashing a world-record £200million on Neymar, the Premier League kept its position as Europe's biggest spender, investing almost twice as much as second-placed Serie A, which paid out £735million on playing talent.

In fact, the combined spend of clubs from Ligue 1, the Bundesliga and La Liga is only £170million more than the Premier League's, although the Spanish transfer window does not close until Friday night.

This summer also saw Premier League clubs return to their traditional position of being net importers of players after making a small profit on player trading with their overseas rivals in January. This summer, the league's net expenditure on foreign transfers was £585million, a decrease from 2016's record of £630million.

"While the transfer record for a single player has again been broken by a major European club, the Premier League's clubs enjoy an unrivalled depth of purchasing power, as a result of the League's relatively equal - and transparent - distribution of broadcast revenues," said Jones.

"Premier League clubs continue to benefit from a virtuous circle: investing record revenues to acquire some of the best playing talent from around the world, which in turn helps the Premier League secure substantial improvements in domestic and international broadcast deals, and helps individual clubs maximise commercial revenues and matchday attendances through stadium improvements and similar long-term investments."

The Premier League's highest spending clubs this summer were Manchester City (£215million), Chelsea (£180million), Manchester United (£145million) and Everton (£145million).

Only four clubs ended up in the black on their transfer dealings: Arsenal, Burnley, Stoke City and Swansea.

For comparison, spending in the Championship was down from £215million last summer to £195million this summer.

In its own analysis of the window, the Premier League noted that the average net spend per club was £33.25million, equivalent to 14.73 per cent of total club revenue, compared to 14.35 per cent last summer.

The league also pointed out that the clubs will invest £443million "in supporting wider English football and communities" this season.