Conn. Agencies Regs. § 31-296-2
In any case in which the employer or the insurer doubts the fact of accident or the causal relationship between the accident and the disability, but wishes to make payment without prejudice and without admitting liability, he shall notify both the claimant and the commissioner by letter that payment will be made without prejudice. Such letter shall contain a statement of the average weekly wage, the compensation disability rate, the number of dependent children or stepchildren and the total weekly benefit to be paid. A formal notice of the employer's intention to contest liability (Form 43) shall accompany such letter to protect the respondent's rights. Payments without prejudice shall be made for not more than six weeks. If, at the end of such period, the employer or insurer has completed his investigation and determines the accident is compensable, a voluntary agreement shall be offered. Otherwise, the employer shall promptly request an informal hearing.
Conn. Agencies Regs. § 31-296-2