> Four months before the theft, on May 4, 1987, Saura Taniguti, then director of Ipasgo, the institute of insurance for civil servants, used police force to prevent one of the owners of IGR, Carlos Figueiredo Bezerril, from removing the radioactive material that had been left behind.

This is the key line for me. Why did Saura Taniguti summon police force to prevent the removal of such a hazardous object?

The link above is helpful but you have to dig through a very long Portuguese website to find this key nugget (via Google translate):

> However, at the end of 1985, this institute stopped working in these facilities and moved to other new facilities. Meanwhile, the property of the clinic's services was disputed in court, and the cobalt 60 teletherapy unit was transferred to the new facilities and the teletherapy unit in Cesio 137 was abandoned in its original place because it was embargoed.

> Most part of the clinic was demolished as well as adjacent properties. The treatment rooms in the fueron were demolished but were in a ruined state, abandoned. The date has not been notified to the licensing authority - Comisión Nacional de Energía Nuclear: CNEN.

https://scienceinfo.net/nuclear-disaster-from-a-stolen-medic... adds that:

> According to [Saura Taniguti], because there was a dispute between IGR and Saint Vincent de Paul Association - which owned the real estate block - where the IGR Hospital was located, and the court had a sealed order and cut it [sic]. security guards should all equipment in the hospital must remain the status quo.

My guess is the events were probably something a bit like the following:

1. IGR decides to relocate.

2. The technicians in IGR seemed very aware of how dangerous the Cesium source was. It was likely installed in a large machine, that would be inaccessible until most of the other items in the facility had been relocated.

3. Furthermore, to move such a source, they would not just pick it up and carry it in their pocket - you'd book perhaps an armored/lead-lined car, carry Gieger counters, dose badges, and wear contamination suits in case of an incident. Speculation: IGR thought it would be prudent to have most of the facility moved by untrained movers, but leave the nuclear source in place to reduce risk of an incident. Once the facility was emptied, they could bring in the the hazmat suits and move the source more safely.

4. All articles agree that the landlord, SVPA, is unhappy. Speculation: IGR had to terminate its lease early, or SVPA couldn't find a new tenant to cover their losses on the space.

5. After the initial move of the "easy" items, SVPA learns some "important equipment" is still on premises. They move to seal the building, to gain leverage in court negotiations.

6. The court negotiations go on for two years. Meanwhile, the developer moves to demolish the property so that it may be redeveloped so they can monetize the land. Speculation: offers were made to move the radiation source, but this would only be allowed if IGR would, for example, agree to pay for the cost of the broken lease and lost rent. (This is almost the exact situation of the SFO Safer, the oil storage unit off the coast of Yemen; people want to make it safe, and have been try to for years; but the group controlling access to the vessel is unwilling to grant free access to it, because the vessel in its current state is too valuable for negotiations).

7. The IGR was prevented "by police" from moving the source on May 4 1987. While the source could have been carried out by one person, nobody who knew how dangerous it was would just casually carry it out. Speculation IGR made a last-ditch to recover the source, and a task force arrived with e.g. Geiger counters, hazmat suits and a containment vessel. This did not go unnoticed -- authorities were notified; police came to enforce the embargo, because once the radiation source was removed, SVPA would lose a key negotiating chip.

That would be my "read between the lines" of how the situation might have played out. Once the leak happened, of course, the finger pointing would begin and presumably someone with sufficient connections to prevent the radiation source from being removed would also have sufficient connections to pin the blame on someone else for having it not removed.

The incident reminds me a bit of the port explosion in Beirut -- authorities were made aware of the danger, but the right thing simply couldn't happen in time, and the entropy of the universe eventually won out.

edit: formatting and correction of acronym