Earth leakage

I have problem of earth leakage at DB which fed from UPS and this (Ddistribution Bboard) supply 20 sub circuit I checked every circuit individually by disconnecting the earth cable from the panel earth bar the result as this

1. I found one instrument cable use as power cable I disconnect the cable from both ends meg test was carried out the result was Okay reconnect the cable at CB side measured the power at the other end (screen as earth conductor) against the earth bar there was 98 VAC
2. I found another power cable its earth cable carry about 98 VAC I did as above I take the cable out from the tray and I reconnect the power again still the earth cable got 98 VAC and some times reach to 130 VAC and at this level UPS CB trip and no alarm at UPS indicate that there was earth fault

please any help can explain this problem