BALTIMORE (Reuters) -- A Baltimore police officer charged with manslaughter over the death of Freddie Gray told another officer the man in their custody appeared to need medical assistance, but none was provided at the time, the Baltimore Sun reported Saturday.

Six Baltimore police officers were charged in connection with the death of Gray, who was black, in April from a spinal injury, which sparked protests and rioting in the city and fueled a debate on police treatment of minorities in the United States.

Gray, 25, was arrested for carrying a knife and was bundled into a transport van while in handcuffs and shackles, and not secured with a seatbelt, officials said.

Prosecutors have said Officer William Porter, who is black and was charged with manslaughter, assault and reckless endangerment in May, was called by Officer Caesar Goodson Jr., the van's driver, to check on Gray's status.

Porter told investigators he informed Goodson, who is also black, the jail booking facility would not process Gray because he was in medical distress, according to an article posted on the Baltimore Sun's website that cited police findings.

The newspaper said it obtained Porter's account from an initial police review of Gray's fatal injury.

Porter also told investigators he wondered whether Gray truly needed medical assistance, even though he requested it, or was faking injury because he wanted to go to a hospital instead of jail, the newspaper reported.

Prosecutors have said that when Goodson and Porter were discussing taking Gray for medical care, a call came in requesting police support, and Goodson drove off with Gray still unsecured in the vehicle.

When Goodson later arrived at a police station, Gray had stopped breathing and was taken to a hospital where he died a week later, prosecutors said.

Some of the officers' accounts initially given to investigators differ from each other, which helps explain why separate trials were ordered for them. That includes Porter, who is expected to testify against Goodson and Sergeant Alicia White, The Sun said.

Goodson is charged with second-degree murder, and White faces the lesser charge of manslaughter.

In a statement to the newspaper from lawyers for all six officers, defense attorney Joseph Murtha characterized police disclosure of their clients' statements as "unfair and unconstitutional."