Prosecutors have asked police to obtain more evidence over allegations that Energy Secretary Chris Huhne dodged a speeding penalty.
The CPS said it had requested additional material after completing a "full review" of the case.
"We have now considered all the evidence submitted to us so far and have completed a full review of the case," a spokeswoman said.
"We have asked Essex Police to obtain further information which they are seeking to gather.
"As a result, this week they were granted a production order for material held by a national newspaper.
"We await the outcome of this. We continue to work closely with the police and hope to reach a decision shortly."