Ajay Katara, a key witness in the sensational Nitish Katara murder case, was on Thursday hospitalised in Ghaziabad with suspected poisoning.
The 35-year-old cousin of Nitish was admitted to a private nursing at around 2 pm, Senior Superintendent of Police Deepak Ratan said.
Suspected poisoning is the cause of his ailment but it was not clear immediately whether he consumed it or someone else administered it on him, he said.
Investigation is being conducted to ascertain the cause of poisoning. Nitish Katara was murdered in February 2002 and Uttar Pradesh politician DP Yadav's son Vikas and his nephew Vishal were the main accused in the crime.
Sources said Ajay was facing some marital problems.