Ashhar Farhan and Raj,
The original email stated that it was there on both transmit and receive. I think that should rule out the relays, any of the transmitter amplifier stages, and the antenna match. I guess it is possible that a bad match could affect the 30 Mhz LPF at the input to the first IF, Still, the double-balanced mixer should isolate the LO from the RF port.
Am I missing something?