The Home Secretary has told the Leveson Inquiry into press ethics that relations between police and journalists will be governed by new "common sense" guidelines.
Theresa May is the first serving minister to give evidence at the inquiry.
The Home Secretary said she had received guidance from police chiefs that recommends officers should not accept gifts, gratuities or hospitality "except if it is of a trivial nature".
Mrs May said it was important officers did not put themselves in a position where "people could feel that they are being influenced by the receipt of such gifts".
The new guidelines, which suggest officers should only have "light lunches" with journalists were drawn up by the Association of Chief Police Officers (ACPO). Previously forces drew up their own guidelines, with wide divisions in what was deemed acceptable.
Education Secretary Michael Gove, a former journalist on The Times, is expected to be questioned later about his relationship with Rupert and James Murdoch, as well as former News International chief executive Rebekah Brooks.
Mr Gove recorded 11 meetings with senior News Corp figures between the May 2010 General Election and July 2011.
Earlier this year he said freedom of speech could be harmed by the "chilling atmosphere" created by the Leveson Inquiry.
Their appearance comes after former Prime Minister Tony Blair told the inquiry he did not make a deal with Mr Murdoch in return for support from his newspapers.