Cambridgeshire Police have sent a second letter to press and broadcast journalists clarifying its request for material relating to the murders of the Soham schoolgirls.
The first request, a lengthy questionnaire, ran into opposition from media organisations. They argued that the trawl for information was far too wide.
Now Detective Chief Superintendent Chris Stevenson has written to journalists "to clarify several issues". In his letter, he wrote: "Firstly, it was not my intention to compromise in any way the integrity and confidentiality of any journalistic source. I am also aware that the sheer breadth of information sought was a cause of concern to you."
Stevenson then formally asked the media to consider providing the police investigation with:
lAll published and unpublished material containing interviews with Ian Huntley and Maxine Carr.
lAll published and unpublished photographs and film footage in which the couple appear.
lAny published and unpublished interviews with third parties which contain any reference to Huntley or Carr.
lInformation concerning "any contractural agreements you may have entered into or attempted to enter into as a result of your work, specifically in relation to the Holly Wells and Jessica Chapman inquiry."
He added: "The sole reason for requesting the material is that it may be of evidential value to the investigation. If you would rather a court order was sought, then would you be kind enough to convey this to the officers making contact with you."
The BBC, ITN and Sky News have already handed over footage after police obtained a court order.
A BBC spokeswoman said it was still "appropriate" for the police to follow normal procedure and obtain a court order if they wanted additional footage. She reiterated the BBC view that such requests should be made to the corporation and not to individual journalists.
John Battle, ITN head of compliance, said as the police request now focuses on material specifically relating to the two defendants the news provider is "presently determining what material we have that falls within the parameters of their requests". But he added that a court order would still be needed if it was to hand over unbroadcast material.
Tom Crone, legal manager of News Group Newspapers, said: "We have no problems with the first two requests. But the third [interviews with third parties] is still too wide, too burdensome and too vague."
On the request for information on contractual agreements, Crone said: "We would comply with the Code of Practice in revealing arrangements, should those people with whom we have made arrangements turn out to be witnesses or give police statements. Our basis is very much that none of the arrangements made is with people who are witnesses or are likely to be witnesses. But, as always happens with these things, as it did with Fred West, events move on and suddenly these people get brought into the police inquiry.
"We would divulge any arrangement with people who come into this category."
By Jon Slattery and Julie Tomlin