Scorned wife Tanya enacted revenge on errant husband Max in the episodes
Complaints about two episodes of EastEnders have been upheld by the BBC.
Viewers complained following two pre-watershed episodes which saw Max Branning drugged, put into a coffin and buried alive by his wife, Tanya.
The BBC's complaints unit said the scenes contained no explicit violence, but the response suggested the impact had been stronger than expected.
The findings would be discussed by the EastEnders team and taken into account in future storylines, it added.
The complaints unit said three viewers had complained that the plotline, screened in March, was inappropriate for a pre-watershed drama series which attracts a family audience.
It said the "potential sensitivity" of the storyline had been recognised by the programme-makers, and it "had been the subject of extensive consultation before transmission".
The scenes did not involve "explicit physical violence", and the programme-makers believed they "would not exceed the expectations of the audience", the unit said.
But it said: "The nature of the response registered...suggested that the emotional impact of the storyline was somewhat stronger than had been considered likely, and that it had caused upset among a segment of the audience which was neither anticipated nor intended.
"The complaints were upheld."
The findings would be discussed amongst the production team and would be taken into account in the development of future story lines, it added.
The two episodes were broadcast on Good Friday and Easter Monday.
Good Friday's episode, which was broadcast at 2030 GMT, saw scorned wife Tanya (Jo Joyner) enact her revenge on errant husband Max (Jake Wood) for his affair with Stacey (Lacey Turner), by drugging him and attempting to bury him alive.
In February, media watchdog Ofcom ruled the soap breached TV regulations in an episode showing a gang attack on the Queen Vic pub.
The media regulator said the soap showed "sustained violence, intimidation and menace" inappropriate for a pre-watershed audience.