CELTIC have apologised to fans after a letter sent to season ticket holders provoked outrage. 

The Scottish champions' supporters liaison officer took to social media to say sorry for the 'confusion' and 'upset' caused by the club's attempt to clarify its position on Thursday.

The letter said that season tickets are "for use of the named season ticket holder only and the use by an third parties, including family and friends is not permitted".

Read more: Celtic season ticket letter over family and friends policy sees fans vent furyBarrhead News:

But following a backlash from disgruntled Hoops fans, the Celtic SLO tried to clear the air on Friday morning. 

A post on Twitter read: "So, the letter was intended to offer clarity on the use of ST's we've recently seen a few examples of season books being used incorrectly, leading to problems for supporters on a match days, it was designed to avoid further problems, apologies for any confusion/upset caused."

Celtic had said that the rule exists to 'ensure safety and security' and keeps the club 'compliant with SPFL regulations'.

But the move provoked an angry response from fans. 

Craig Yule wrote: "That letter's an absolute disgrace. Would you rather season ticket holders pay and [not] turn up like last night?"

Another Daniel Maxwell added: "It’s my seat/ticket, I’ve paid my money for it, if I can’t make it and give it to someone else that I trust then that’s on me. Half the stewards outside the ground can’t tell the time let alone do security checks, waste of a tree lettering us all. Letter is condescending at best."

Another said: “Total nonsense from the club and I’ll give my season ticket to whoever I like if I can’t make a game.”