Time limit for interrogation

I was taken in for police interview and spent the entire day from 9am to 7pm, and then admitted to bail after having to plead with the officer that I did not want to be held in custody as it was a minor bailable offence which i was denying in any case. I was told that the police in charge who could allow bail was attending a function but I finally managed to get hold of him and get bail. My question is on how long can an officer interview me because by the end of the interview I was extremely tired and stressed. The officer kept on asking the same question over and over again, slowly writing on his notepad. Is there no time limit under the law?
CC, Moshi

The Criminal Procedure Act has provided under section 50 that (1) for the purpose of this Act, the period available for interviewing a person who is in restraint in respect of an offence is– (a) subject to paragraph (b), the basic period available for interviewing the person, that is to say, the period of four hours commencing at the time when he was taken under restraint in respect of the offence. Paragraph (b) in principle excludes time when you are waiting for your lawyer, or the time when you are not being interviewed.

However, the basic time frame for the interview is 4 hours, which however can be extended to another four hours as provided under section 51. Section 51 states that (1) where a person is in lawful custody in respect of an offence during the basic period available for interviewing a person, but has not been charged with the offence, and it appears to the police officer in charge of investigating the offence, for reasonable cause, that it is necessary that the person be further interviewed, he may (a) extend the interview for a period not exceeding eight hours and inform the person concerned accordingly; or (b) either before the expiration of the original period or that of the extended period, make application to a magistrate for a further extension of that period. (2) A police officer shall not frivolously or vexatiously extend the basic period available for interviewing a person, but any person in respect of whose interview the basic period is extended pursuant to paragraph (a) of subsection (1), may petition for damages or compensation against frivolous or vexatious extension of the basic period, the burden of proof of which shall lie upon him.