Andy Coulson, the former editor of the News of the World and the prime minister's former personal communications director, is reportedly refusing to supply more evidence to the Commons select committee that is investigating phone hacking.

His solicitors have written to the culture, media and sport committee declining an invitation to "reconsider, or make any additional comments on," the evidence he gave to the committee in 2009.

Coulson's lawyers cited "concerns" about "parallel inquiries and investigations and the publicity generated by them".

Coulson resigned from the News International paper in 2007 after its former royal editor Clive Goodman was jailed on phone-hacking offences.

He has consistently denied knowing that phone hacking took place but last month a previously unseen letter from Goodman emerged that claimed phone hacking was "widely discussed" at editorial conferences until Coulson banned mentions of it. Goodman's letter also claimed that Coulson had offered to let him keep his job if he agreed not to implicate the paper in hacking when it came to court.

The chairman of select committee, John Whittingdale, wrote to Coulson the day this letter was released into the public domain, inviting him to consider whether his previous denials of knowledge of phone hacking should be amended.

Coulson's solicitors at law firm DLA Piper said in their reply to Whittingdale: "We have expressed our concerns to you previously about the effects of the parallel inquiries and investigations and the publicity generated by them. Given those concerns … our client does not wish to make any additional comments on the evidence he gave to the committee."

DLA Piper refused to comment.

• This article was amended on 8 September 2011. The original said that Andy Coulson had refused to reappear before the Commons select committee that is investigating phone hacking. In fact he declined an invitation to provide additional comments, in a written reply, to the evidence he gave in 2009. This has been corrected.

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