A police spokesperson said: "Police were called at 10:37am today (Wednesday) to a concern for safety on Jack Lane in Batley.
"Police officers and ambulance service attended to discover a male had collapsed in the street. He was unresponsive and was pronounced deceased.
"A police cordon is in place and enquiries are ongoing to establish the circumstances.
"Anyone who has any information or witnessed anything in the area is asked to contact the police via 101 quoting log number *579 of 10 October."