Pig heads have been dumped outside an old ambulance station after it was claimed the building was being illegally used as a mosque.
Solihull council is investigating whether the community centre is being used for regular worship, which could break planning laws.
A carrier bag believed to have been used to carry the meat is being examined by forensic experts.
The incident on Sunday night is being treated as a hate crime, police said.
CCTV footage appears to show a man putting a package on the centre’s doorstep before driving away, according to West Midlands Police.
“We’ve secured good quality CCTV of the culprits and my detectives are making good progress with the investigation. The forensic evidence we have is also very strong and we expect a result from that in the coming days,” Ch Supt Alex Murray said.
Windows on the same building, on Hermitage Road, were also damaged on the previous evening.
Some local residents have described the atmosphere in the town as tense.
“I’ve been living in Solihull for 10 to 15 years now and it’s never been as frightening to live in this area as a Muslim as it is now,” local resident Mohammed Abdullah said.
Local imam Dr Issam Ghannam, however, said community relations in the town were very good and described it an isolated incident, but said the actions of “a minority” were a “threat to the community”.
The council launched its own inquiry after residents claimed they had not been consulted about the building “becoming a mosque”.
In April 2014, the council granted permission to change its use from an ambulance station into a training and conference centre.
More than 3,000 people have so far signed an online petition against its use for worship.