498a is non-bailable offence. So it is foolish that station bail is permitted to the accused. I would opine that the original querist should seek AB from the court. Though, SC has issued guidelines to not to arrest the accused, if he is cooperating with the police in investigation, but who cares about such toothless guidelines of SC. Consult some local lawyer please.
In my understanding, police cannot arrest a person just because the allegations pertain to a cognisable and non-bailable offence; there need to legal necesssity and justification. Moreover, in 498A cases the police are strict instruction except with the express approval of the SP of the District.
Mr. P. Venu, every member of LCI would be highly obliged, if you could provide the strict instructions for the police in cases under 498A which only is known to you. BTW, who has issued those alleged instructions? Is it state of Kerala, HC Kerala, the SC of India or the president of India?