Barcelona must make 200m in summer sales if they're to buy before the start of the next season.
Barca's financial issues are well-documented, and they now face a race to procure the necessary funds in time to have any impact on the upcoming summer window.
This latest update comes less than a month after Barca president Joan Laporta claimed the club was in a strong position, vowed to cut 150m from the wage bill, and stated that no player sales would be necessary.
"As of today, Barcelona doesn't have any room in its budget to spend in the upcoming transfer window," LaLiga chief Javier Tebas said on Thursday in London, at the Financial Times' Business of Football summit.
"Barcelona has been involved in questionable behaviour which has had an impact on LaLiga and we are acting accordingly. We have ruled that they can no longer sign more players.
"They sold off 620m (700m) in TV rights and tried to find different ways to solve the situation but they won't be able to do that next season. We have strict economic controls. At the end of each window, we tell all the clubs in LaLiga what they can spend.
"In the case of Barcelona, they have to drop from spending on wages and transfers from 532m to 399m (650m to 450m), so it's a budget of minus 177m (200m).
"They have to reduce their investment in players and we have encouraged them to sell players because, for every amount they raise in sales, they can spend 40 per cent of that."
