This was confirmed by AM Costa Rica:
Proposal for oil drilling brings two quick, negative reponses
By the A.M. Costa Rica staff The second-largest political party in the legislature and a group of long-time foes to oil drilling have come out against a plan by China to seek petroleum here.
This sparked quick replies from the PAC party and
Oilwatch Also in La Nacion today:
Chinese Mission will Analyze EnergyThey stated that the Chinese would be analyzing the possibilities and that the moratorium does not exist - it was never formalized by Pacheco in a decree

I'm not sure about that, although I know it was never passed as a law.