ImportError: The `scipy` install you are using seems to be broken, (extension modules cannot be imported), please try reinstalling

I'm coniststently getting this error when trying to use scipy or sklearn packages in Python3.9 via a Jupyter notebook.

The error is:

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
~/opt/anaconda3/lib/python3.9/site-packages/scipy/__init__.py in <module>
    165     try:
--> 166         from scipy._lib._ccallback import LowLevelCallable
    167     except ImportError as e:

~/opt/anaconda3/lib/python3.9/site-packages/scipy/_lib/_ccallback.py in <module>
----> 1 from . import _ccallback_c
      2 
      3 import ctypes

ImportError: dlopen(/Users/dn/opt/anaconda3/lib/python3.9/site-packages/scipy/_lib/_ccallback_c.cpython-39-darwin.so, 0x0002): tried: '/Users/dn/opt/anaconda3/lib/python3.9/site-packages/scipy/_lib/_ccallback_c.cpython-39-darwin.so' (mach-o file, but is an incompatible architecture (have 'arm64', need 'x86_64'))

The above exception was the direct cause of the following exception:

ImportError                               Traceback (most recent call last)
/var/folders/d7/q_fznsr95_97r6lp_mx_vp640000gn/T/ipykernel_37825/912110602.py in <module>
      1 #import scipy
----> 2 from sklearn.ensemble import RandomForestClassifier #Picks up non-linearities

~/opt/anaconda3/lib/python3.9/site-packages/sklearn/__init__.py in <module>
     80     from . import _distributor_init  # noqa: F401
     81     from . import __check_build  # noqa: F401
---> 82     from .base import clone
     83     from .utils._show_versions import show_versions
     84 

~/opt/anaconda3/lib/python3.9/site-packages/sklearn/base.py in <module>
     15 from . import __version__
     16 from ._config import get_config
---> 17 from .utils import _IS_32BIT
     18 from .utils._tags import (
     19     _DEFAULT_TAGS,

~/opt/anaconda3/lib/python3.9/site-packages/sklearn/utils/__init__.py in <module>
     20 import warnings
     21 import numpy as np
---> 22 from scipy.sparse import issparse
     23 
     24 from .murmurhash import murmurhash3_32

~/opt/anaconda3/lib/python3.9/site-packages/scipy/__init__.py in <module>
    169               "(extension modules cannot be imported), " + \
    170               "please try reinstalling."
--> 171         raise ImportError(msg) from e
    172 
    173     from scipy._lib._testutils import PytestTester

ImportError: The `scipy` install you are using seems to be broken, (extension modules cannot be imported), please try reinstalling.

I've tried uninstalling and reinstalling scipy both as it describes in the documentation as well as using homebrew but still getting the same error.

Does anyone have an idea how this can be resolved? Scipy was working on my machine a few weeks ago - not sure what has changed in the past weeks.

Any help much appreciated.