In her petition, 65-year old Rajammal, a retired headmistress, said she feared arrest in the case registered in 2006 in connection with the death of Biju's first wife Reshmi.
Justice S S Sateeshchandran granted the bail and asked her to execute a bond for Rs 20,000 and one solvent surety for the like amount, appear before investigating officials whenever asked and should not leave the state.
Rajammal and Biju Radhakrishnan have been charged with offences under Sec 302 (murder), 498A (husband or relative of husband of a woman subjected to cruelty) and 201 (causing disappearance of evidence of offence).