Spanish Liga clubs sold over £404 million of talent to foreign clubs over the summer.
The Daily Mail says the figures compiled by Barcelona-based Prime Time Sport underlined how Spanish top-flight teams, excluding wealthy Real Madrid and Barcelona, are increasingly being forced to cash in on top performers to stay afloat.
They also suggested UEFA's Financial Fair Play (FFP) rules, currently being phased in and designed to prevent clubs spending more than they earn, are beginning to bite.
Almost a third of income, or £117m, came from deals with clubs outside Spain.
The majority of players were sold to English Premier League sides, including Mesut Ozil leaving Real Madrid for Arsenal, Alvaro Negredo and Jesus Navas joining Manchester City from Sevilla and Roberto Soldado switching to Tottenham Hotspur from Valencia, though Real also bought domestically in the likes of Isco.
La Liga clubs spent £337m buying players, the second highest amount ever, yielding a net profit of around £67m, with Real Madrid (£154m) and Barcelona (£48m) accounting for 62 percent of the outlay.
