No. It's not illegal, per se, to tell lies.
Your statement was not defamatory, so the law relating to libel is irrelevant. (Even if your statement was defamatory, the statement would have had to have been 'published', e.g. on an internet forum, before any legal action could have been taken against you).
Your statement did not make any threats (other than of police action), so the laws relating to such things as 'threatening behaviour' aren't relevant.
Similarly, there's nothing in the 'blackmail' laws which could be used against you.
Chris
PS: Don't necessarily expect the police to take your complaint very seriously. Unless you can show that you've suffered financial loss they might be very dismissive in their response. Further don't assume that getting the IP address traced will automatically help. (Many of my posts to internet sites currently show that I'm using a Slovakian ISP, rather than my real one here in the UK. It only takes a few seconds to configure a proxy server!).