UEFA has confirmed that nine clubs are to be investigated further over a possible failure to comply with Financial Fair Play guidelines.
European football's governing body has been examining the case of 76 clubs who were requested to provide additional information to prove they have adhered to FFP rules for the 2013-14 season.
After further assessment, UEFA has now revealed that investigations will continue into nine of those 76 clubs who took part in either the Champions League or Europa League this season, although none have been mentioned by name.
A statement released on UEFA's official website read: "Following the period in which the Club Financial Control Body (CFCB) Investigatory Chamber monitored the compliance of clubs with Financial Fair Play (FFP) regulations, UEFA can confirm that of the 237 clubs which entered the 2013/14 UEFA club competitions (and were thus subject to this season's break-even requirements), 76 were requested to submit additional information. From that group, the examination as regards 67 clubs has come to an end and continues only in relation to the nine remaining clubs.
"Further information shall be provided once this process has been completed."
The aim of FFP rules is to ensure clubs do not spend more than they earn over a given period of time and therefore do not fall into debt or tax arrears.
Arsenal boss Arsene Wenger this week called for strong punishments for clubs who fail to comply with FFP regulations, which state that no club is permitted a loss of more than 45 million euros over the 2011-12 and 2012-13 seasons.